My badges on some of my ludwig gear are pointy.(all of them on the vista lite) So I know now that they were made during the 70's .... :-) Another something I found was this book wich claims to have a complete dating guide.
Vistalite Drums is a web site for the history and documentation of Ludwig Vistalite Drums.
Vistalite Drum Sets, Vistalite Snare Drums in a variety of patters.
Fixing vistalite shells and cleaning vistalite shells.
The Acrolite Snare Drum history section will document the drum from the early 60's version to the newer Acrolite still being made by Ludwig.